1. Field of the Invention
The invention relates to a vibration damper whose cylinder tube is divided into two work chambers by a piston attached to a piston rod, whereby a damping valve includes a damping valve body, into the main body of which damping valve embossed areas have been formed which serve as valve support surfaces with fluid passages, which fluid passages are covered by valve disks on the valve support surfaces, and whereby the damping valve body is disk-shaped.
2. Background Information
German Laid Open Patent Application No. 20 59 682 discloses a vibration damper whose cylinder tube is divided into two work chambers by a piston attached to a piston rod, whereby the piston includes a piston body with fluid passages covered by valve disks on support bodies with valve support surfaces, and the piston body is in sliding contact with the cylinder tube via at least one piston ring.
Publications European Patent No. 160 275 A1 and German Patent No. 43 02 624 C1 disclose that a multipartite piston body can be manufactured from stamped sheet instead of a sintered material. Due to the relatively complex stampings, manufacturing tolerances have a negative influence on the permissible damping force distribution. That is, to achieve a permissible damping force distribution, the parts of a piston body must be manufactured within certain tolerances. The complexity of the parts make achieving the required tolerances difficult to achieve by the stamping process.
German Patent No. 44 10 996 CI describes a vibration damper whose cylinder tube is divided into two work chambers by a piston attached to a piston rod, whereby the piston includes a piston body with fluid passages covered by valve disks on support bodies with valve support surfaces, and the piston body is in sliding contact with the cylinder tube via at least one piston ring. The piston body is disk-shaped, with embossed areas on the piston body forming the valve support surfaces. Damping valves of various designs are described, with none of the variants having a progressive damping force characteristic. A significant advantage of the piston is its extremely low structural height.
A vibration damper as disclosed in German Patent No. 24 24 040 A1 teaches that constriction of the cross-section for a progressive end section of the damping force characteristic is associated with a cross section reduction, which is problematic with respect to application to a flat piston given the available space.